Railway truck bolster snubber

ABSTRACT

A helical torsional spring is utilized to urge the friction shoes of a snubbing arrangement upwardly into the inclined bolster pockets in which the shoes are carried. A wedge between the bolster bottom wall and a U-shaped central portion of the spring is used to apply a torsional load on the spring.

United States Patent- Carl E. Tack Elmhurst, Ill.

June 12, 1968 Apr. 13, 1971 Amsted Industries Incorporated Chicago, Ill.

lnventor Appl. No. Filed Patented Assignee RAILWAY TRUCK BOLSTER SNUBBER13 Claims, 5 Drawing Figs.

US. Cl 105/197, 105/193, 267/3, 267/4 Int. Cl B611 3/08, B6lf 5/06, B6lf5/12 Field of Search 105/197,

197 (D), 197 (DB), 193,267/3, 4

References Cited UNITED STATES PATENTS 9/1936 Goodwin 105/197(D) 6/1948Lehrman... 105/197(D) 2/1954 Spenner 105/l97(DB) 6/1956 Heater et al.105/197(D) 3/1958 Williams lO5/l97(D) 12/1960 Ingram et al l05/308(P)Primary Examiner-Arthur L. La Point Assistant Examiner-l-loward BeltranAtt0meysWalter L. Schlegel, Jr. and Russell W. Pyle ABSTRACT: A helicaltorsional spring is utilized to urge the friction shoes of a snubbingarrangement upwardly into the inclined bolster pockets in which theshoes are carried. A wedge between the bolster bottom wall and aU-shaped central portion of the spring is used to apply a torsional loadon the spring.

Patnted April 13, 1971 2 Sheets-Sheet 1 Zwenfm Carl Z. Y-ZwL PatentedApril 13, 1971 2 Sheets-Sheet 2 I u/e 1 LZUY- c'a. A? 'IL'LCL a 4RAILWAY 'II'RIUCII BOILS'IIER SNIJBBER This invention relates tosnubbing arrangements for railway vehicles and more particularly to asnubbing arrangement utilizing friction shoes operatively carried inwedge-shaped pockets at opposite sides of a truck bolster structure,wherein the friction shoes are urged into sliding frictional contactwith wear plates mounted on the vertical columns of the side frames ofthe truck.

Two primary concepts have developed in the use of a spring force to urgefriction shoes into engagement with the side frame columns and otherfriction-snubbing surfaces of the truck. One concept involves theapplication of a spring under compression between the bolster and thefriction shoe mounted in the bolster structure. In the usualconstruction, the friction shoe is borne upwardly against the inclinedwalls of pockets formed in the bolster and outwardly against the sideframe columns, the spring exerting a substantially constant forceagainst the friction shoe regardless of vertical movements of thebolster. The spring may be mounted under compression in a cavity withinthe friction shoe or in other locations, but space limitations anddifficulties of installation have sometimes presented problems in theuse of such arrangements.

The other concept involves the applicationof one or more control springsunder compression between a member of the truck side frame and thefriction shoe operatively mounted in the bolster. Since the truckbolster supports the weight of the car body and is resiliently supportedin the side frames, the force exerted on the friction shoes is variableand increases as the weight on the bolster increases. Because of spacelimitations and the tendency of such control springs to take permanentset after use over a period of time, this type of arrangement cannotprovide adequate control forces under all conditions of load and normalwear of friction elements.

Accordingly, an object of this invention is to insure adequate dampingthrough the complete range of car load and normal wear conditions byincorporating a constant force to provide sufficient damping of an emptyor lightly loaded vehicle, along with a variable force to add dampingfor a range of loaded vehicle conditions.

Another object of this invention is to provide a snubbing arrangementutilizing a unique constant torsional spring force that may be usedeither in conjunction with a variable compression spring force or alone.

A further object of this invention is the provision of a snubbingarrangement including a torsional spring to which an independenttorsional load may be applied after installation of such spring.

Other objects will become apparent from the following description andappended claims, taken in connection with the accompanying drawingswherein;

FIG. I is a fragmentary elevational view, partly in section, of arailway truclt that incorporates features of the presently describedinvention;

FIG. 2 is a fragmentary side view of a portion of the bolster thatincorporates features of the present invention;

FIG. 3 is a fragmentary plan view of the bolster shown in FIG. 2;

FIG. 4 is a plan view of the torsional spring utilized in the preferredembodiment of the present invention; and

FIG. 5 is an elevational view of the wedge utilized with the torsionalspring described herein.

With more particular reference to FIG. l, the improvements of thepresent invention are shown embodied in a railway car truck whichgenerally comprises a pair of side frames, one of which 16 is shown,interconnected by a bolster I2 resiliently supported at its ends onspring groups 114. Each side frame includes a top or compression member16 and a bottom or tension member 18 interconnected by spaced verticalcolumns 20 which together define an opening to receive the end of thebolster ll2.

Inasmuch as the opposite sides of the truclt herein shown includeidentical parts, the drawings and description, for the sake of brevity,will be confined to one side of the truck, it

being understood that a complete truck includes like parts at both sidesthereof.

As best shown in FIGS. 1-3, the snubbing arrangement generally comprisesa pair of wedge-shaped pockets 22 (FIG. 3) formed in opposite sides ofthe bolster 12 near the end thereof, said pockets opening outwardlytoward the side frame columns 20 and having an inclined wall 24. Afriction shoe 26 is operatively carried in each pocket 22, and includesan inclined surface 28 corresponding to and frictionally engaging theinclined wall 24 of the pocket, as well as a vertical surface 30 forfrictionally engaging vertical wear plates 32 mounted on the side framecolumns 20.

As shown in FIG. 1, if a variable spring force on the friction shoes isdesired, this may be accomplished by the use of one or more controlsprings 34 extending between the friction shoe 26 and a correspondinglocation on the tension member 18 of the side frame It). The controlspring 34 serves to urge the friction shoe 26 upwardly into wedgingengagement between the inclined wall 24 of the bolster pocket 22 and thewear plate 32 on the side frame column 20.

As illustrated in FIGS. ll4, a constant spring force on the frictionshoes is provided by a helical torsional spring 36. As best shown inFIGS. 24, this spring includes two separate helical portions 38 arrangedaround a common horizontal axis and interconnected by a U-shaped portion40 extending away from said axis. The free ends of the helical portions38 terminate in respective substantially straight extensions 42, whichalso extend away from the horizontal axis of the spring. As will behereinafter more fully explained, the U-shaped portion 40 forms aconvenient lever to which a torque may be separately applied forimparting a torsional load to the entire spring, which causes theextensions 42 to act as resilient levers for engaging and urging thefriction shoes 26.

As shown in FIGS. l-3, the torsional spring 36 is placed in operativeposition by first inserting the end extensions thereof 42 throughrespective elongated vertical slots 44 in the outboard sides of thepockets 22 on both sides of the bolster and into a respective cavity 46formed within each friction shoe 26. When so inserted, the torsionalspring 36 is designed such that the helical and U-shaped portionsthereof, 33 and 40, respectively, will lie on the bottom wall 48 of thebolster 12, while the end extensions 42 will be engageable withrespective friction shoes 26 within the respective cavities 46 thereof.It will also be noted that the spring is installed in a substantiallyunstressed condition, thereby greatly facilitating its insertion andremoval.

The cavity 46 of the friction shoe 26 is provided with a transversevertical wall 41 extending from the top of said cavity downwardly for aportion of the height of said cavity and extending between the walls ofthe inclined surface 28 and the vertical surface 30 of the frictionshoe. As shown in FIGS. 1 and 2, the end extensions 42 of the torsionalspring 36, when in operative position, are engageable with the lowersurface of the transverse vertical wall 41. The transverse vertical wall41 also serves the useful function of providing additional internalsupport for the friction shoe 26.

Means are provided for applying a torsional load to the torsional spring36 after its installation which means may comprise a wedge, generallyindicated at 50, which is inserted or driven between the U-shapedportion 40 of said spring and the bolster bottom wall 48 after saidspring has been placed in position. As best shown in FIG. 3, the wedge50 includes a pair of spaced legs 52 that straddle the central verticalweb 54 of the bolster. When viewed from the side, as shown in FIG. 5,the wedge 50 may be seen to include an upper inclined portion 56 slopingupwardly to merge with a horizontal portion 53 upon which the U-shapedportion 40 of the torsional spring 36 rests when in assembled position.The wedge 50 also includes a raised head 60 and an upwardly inclined toe62, which prevent the spring 36 from becoming dislodged during and afterassembly. A locking lug 64 may be provided on the bottom of the wedge 30to engage and lock with a corresponding cavity 66 (FIG. 2) upon assemblyof said wedge.

When the wedge 50 is installed, a torque is applied to the U- shapedportion of the torsional spring 36, thereby imparting a torsional loadto said spring, which causes the free end extensions thereof 42 to beurged upwardly against the internal transverse vertical wall 41 of eachfriction shoe 26. A constant force is thereby applied to urge thefriction shoe 26 upwardly into wedging engagement between the inclinedwall 24 of the bolster pocket 22 and the wear plate 32 of the side framecolumn 20. lt may thus be seen that the torsional spring and wedgearrangement may be used alone or in combination with the variable springforce herein before described.

lclaim:

1. In a railway car truck including side frames interconnected by abolster the combination of friction shoe means carried by said bolsterfor frictional contact with said side frames, and preloaded torsionalspring means for applying a constant force to said friction shoe meansand urging said friction shoe means into frictional contact with saidside frames, said torsional spring means being carried by said bolsterand including an arm engaging said friction shoe means.

2. The invention according to claim 1 wherein means are provided forapplying a constant torsional load to said torsional spring means.

3. The invention according to claim 1 wherein said torsional springmeans further comprises a pair of spaced helical coil portionspositioned horizontally on said bolster and interconnected by a U-shapedportion and extensions from said helical coil portions engageable withsaid friction shoe means.

4. The invention according to claim 3 wherein wedge means is appliedbetween the bolster and the U-shaped portion of said torsional springmeans for imparting a torsional load thereto.

5. In conjunction with a railway car truck including a bolsterresiliently supported between spaced side frames between spaced verticalcolumns thereof, said bolster including pockets on both sides thereofand friction shoes carried in said pockets wedgingly interposed betweensaid pockets and said side frame columns, spring means for urging saidfriction shoe means between said pockets and said side frame columns,said spring means comprising compression spring means subjacent eachfriction shoe and extending between said shoe and a member of the sideframe, and torsional spring means positioned on said bolster, saidtorsional spring means having extensions engaging said friction shoes,and means for supplying a torsional load to said torsional spring means.

6. In conjunction with a railway car truck including a bolsterresiliently supported near its ends between vertical columns of sideframes wherein the bolster includes a pocket having an inclined walladjacent each side frame column and a friction shoe carried by eachpocket including an inclined surface corresponding to the inclined wallof the bolster pocket and a vertical surface in sliding frictionalengagement with said side frame columns, means for urging the frictionshoes on both sides of said bolster upwardly into wedging engagementbetween the inclined walls of said bolster pockets and said side framecolumns, said means comprising a spring horizontally positioned near theend of said bolster on the bottom wall thereof, said spring includingtwo separate helical coil portions having a common horizontal axis andinterconnected by a U-shaped portion, said U-shaped portion extendinginboard within said bolster and away from said axis, said spring alsoincluding a substantially straight extension from each helical coilportion thereof for engagement with respective friction shoes, a cavityin each friction shoe for engagement by respective straight extensions,an elongated vertical slot in each bolster pocket for admitting saidstraight extensions, and means for applying torque to the U-shapedportion of said spring in such a direction as to urge both frictionshoes simultaneously upwardly.

7. The invention according to claim 6 wherein said lastmentioned meanscomprises a wedge driven between said bolster bottom wall andtheU-shaped portion of said spring.

8. The invention according to claim 7 wherein said wedge includes anupper inclined surface merging with a substantially horizontal surfacefor retaining said U-shaped portion, a raised head and toe portion toprevent accidental dislodgement of said wedge, and a locking lug on thebottom of said wedge engageable with a recess in said bolster bottomwall.

9. The invention according to claim 6 wherein a wall is provided withinthe cavity of each friction shoe between the walls of the inclined andvertical friction surfaces thereof, said wall extending from the top ofsaid cavity downwardly for a portion of the height thereof.

10. The invention according to claim 6 wherein each side frame includesa compression and tension member, and wherein at least one compressionspring is provided subjacent each shoe between said shoe and saidtension member.

11. A railway car truck comprising a side frame having tension andcompression members, and spaced columns extending between said membersto define therewith a bolster opening, a bolster structure resilientlysupported from said frame in said opening, said structure comprising abottom wall and spaced wedge walls diverging upwardly from said bottomwall toward respective columns, friction means on said columns, frictionshoe means for engaging respective wedge walls and related frictionmeans, a pair of substantially coaxial coil springs having their axesparallel with said bottom wall and engageable therewith, remote ends ofsaid springs being engaged with downwardly facing surfaces of respectivefriction shoe means, and wedge means between said bottom wall and theinner ends of said coil springs for urging said inner ends upwardlythereby developing torsional forces in said springs to urge saidfriction shoe means against respective wedge walls and friction means.

12. A railway car truck according to claim 11 wherein compression springmeans are interposed between each friction shoe means and said tensionmember.

13. In a railway car truck including a side frame, a bolster structuresupported on springs in said side frame, and friction wedge meanscarried by said bolster construction for frictional contact withcorresponding locations on said side frames; means for urging saidfriction wedge means into such frictional contact comprising springmeans between the bolster and said friction wedge means for providing aconstant force to said friction wedge means and means between said sideframe and said friction wedge means for providing an additional,variable force to said friction wedge means.

1. In a railway car truck including side frames interconnected by abolster the combination of friction shoe means carried by said bolsterfor frictional contact with said side frames, and preloaded torsionalspring means for applying a constant force to said friction shoe meansand urging said friction shoe means into frictional contact with saidside frames, said torsional spring means being carried by said bolsterand including an arm engaging said friction shoe means.
 2. The inventionaccording to claim 1 wherein means are provided for applying a constanttorsional load to said torsional spring means.
 3. The inventionaccording to claim 1 wherein said torsional spring means furthercomprises a pair of spaced helical coil portions positioned horizontallyon said bolster and interconnected by a U-shaped portion and extensionsfrom said helical coil portions engageable with said friction shoemeans.
 4. The invention according to claim 3 wherein wedge means isapplied between the bolster and the U-shaped portion of said torsionalspring means for imparting a torsional load thereto.
 5. In conjunctionwith a railway car truck including a bolster resiliently supportedbetween spaced side frames between spaced vertical columns thereof, saidbolster including pockets on both sides thereof and friction shoescarried in said pockets wedgingly interposed between said pockets andsaid side frame columns, spring means for urging said friction shoemeans between said pockets and said side frame columns, said springmeans comprising compression spring means subjacent each friction shoeand extending between said shoe and a member of the side frame, andtorsional spring means positioned on said bolster, said torsional springmeans having extensions engaging said friction shoes, and means forsupplying a torsional load to said torsional spring means.
 6. Inconjunction with a railway car truck including a bolster resilientlysupported near its endS between vertical columns of side frames whereinthe bolster includes a pocket having an inclined wall adjacent each sideframe column and a friction shoe carried by each pocket including aninclined surface corresponding to the inclined wall of the bolsterpocket and a vertical surface in sliding frictional engagement with saidside frame columns, means for urging the friction shoes on both sides ofsaid bolster upwardly into wedging engagement between the inclined wallsof said bolster pockets and said side frame columns, said meanscomprising a spring horizontally positioned near the end of said bolsteron the bottom wall thereof, said spring including two separate helicalcoil portions having a common horizontal axis and interconnected by aU-shaped portion, said U-shaped portion extending inboard within saidbolster and away from said axis, said spring also including asubstantially straight extension from each helical coil portion thereoffor engagement with respective friction shoes, a cavity in each frictionshoe for engagement by respective straight extensions, an elongatedvertical slot in each bolster pocket for admitting said straightextensions, and means for applying torque to the U-shaped portion ofsaid spring in such a direction as to urge both friction shoessimultaneously upwardly.
 7. The invention according to claim 6 whereinsaid last-mentioned means comprises a wedge driven between said bolsterbottom wall and the U-shaped portion of said spring.
 8. The inventionaccording to claim 7 wherein said wedge includes an upper inclinedsurface merging with a substantially horizontal surface for retainingsaid U-shaped portion, a raised head and toe portion to preventaccidental dislodgement of said wedge, and a locking lug on the bottomof said wedge engageable with a recess in said bolster bottom wall. 9.The invention according to claim 6 wherein a wall is provided within thecavity of each friction shoe between the walls of the inclined andvertical friction surfaces thereof, said wall extending from the top ofsaid cavity downwardly for a portion of the height thereof.
 10. Theinvention according to claim 6 wherein each side frame includes acompression and tension member, and wherein at least one compressionspring is provided subjacent each shoe between said shoe and saidtension member.
 11. A railway car truck comprising a side frame havingtension and compression members, and spaced columns extending betweensaid members to define therewith a bolster opening, a bolster structureresiliently supported from said frame in said opening, said structurecomprising a bottom wall and spaced wedge walls diverging upwardly fromsaid bottom wall toward respective columns, friction means on saidcolumns, friction shoe means for engaging respective wedge walls andrelated friction means, a pair of substantially coaxial coil springshaving their axes parallel with said bottom wall and engageabletherewith, remote ends of said springs being engaged with downwardlyfacing surfaces of respective friction shoe means, and wedge meansbetween said bottom wall and the inner ends of said coil springs forurging said inner ends upwardly thereby developing torsional forces insaid springs to urge said friction shoe means against respective wedgewalls and friction means.
 12. A railway car truck according to claim 11wherein compression spring means are interposed between each frictionshoe means and said tension member.
 13. In a railway car truck includinga side frame, a bolster structure supported on springs in said sideframe, and friction wedge means carried by said bolster construction forfrictional contact with corresponding locations on said side frames;means for urging said friction wedge means into such frictional contactcomprising spring means between the bolster and said friction wedgemeans for providing a constant force to said friction wedge means andmeans between said side frame and said friction wedge means forproviding an additional, variable force to said friction wedge means.